On 21 July, AVO raised the Volcano Alert Level for Cleveland to Watch and the Aviation Color Code to Orange based on reports from pilots and observers on fishing boats. Reports from fishing boats indicated that an eruption started at about 1200 and ash near sea level may have drifted NW. Pilots reported that an ash-and-steam plume rose to altitudes of 4.6-5.2 km (15,000-17,000 ft) a.s.l. and drifted SE. Observations of satellite imagery on 22 July revealed a steam plume possibly containing some ash drifting more than 50 km ESE at altitudes of 3-6.1 km (10,000-20,000 ft) a.s.l. A strong thermal anomaly interpreted as a possible lava flow was also present in the imagery.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Based on a pilot report and inconclusive observations of satellite imagery, the Darwin VAAC reported that on 17 July a possible ash plume from Galunggung rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted SW. CVGHM did not report eruptive activity and advised that the activity status was "normal."

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

SERNAGEOMIN reported that after increased seismicity at Llaima on 14 July, an ash plume rose to an altitude of 5.6 km (18,400 ft) a.s.l. Less than two hours later, very intense orange and red incandescence was seen through breaks in the cloud cover near the summit and at the base of the W flank. At 1915 a vigorous Strombolian eruption ejected incandescent pyroclastic material from the N vent in the main crater to heights of 500 m above the summit. Seismicity and the intensity of the explosions decreased later that day. On 15 July, diffuse ash emissions rose to an altitude of 3.4 km (11,200 ft) a.s.l. Ash and tephra covered areas of the SSE flank. Seismic activity decreased during 16-18 July.

On 19 July, seismicity again increased and ash-and-gas plumes rose to an altitude of 3.3 km (10,800 ft) a.s.l. and drifted SE. The emissions became more intense and frequent, and one explosion produced an ash plume to an altitude of 4.1 km (13,500 ft) a.s.l. Ash and tephra fell on the SE flank. Later that day, constant explosions ejected incandescent material 500 m above the summit that fell near the crater. Steam plumes emitted from the W flank possibly indicated the presence of a new lava flow along with mobile incandescent blocks from a previous lava flow. After another brief period of calm, vapor emissions increased and were followed by strong explosions and lava flows. The Alert level remained at Yellow.

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

AVO reported that during 15-16 July seismicity from Okmok changed from nearly continuous to episodic volcanic tremor, and the overall seismic intensity declined. Satellite imagery indicated elevated surface temperatures in the NE sector of the caldera; meteorological clouds obscured views. On 16 July, the Volcano Alert Level was lowered to Watch and the Aviation Color Code was lowered to Orange. On 17 July, a pilot reported that an ash plume rose to altitudes of 4.6-6.1 km (15,000-20,000) a.s.l. and drifted E and NE. On 18 July, AVO indicated that the eruption was episodic, with occasional ash-producing explosions occurring every 15 to 30 minutes. The plumes from these explosions were limited to about 6.1 km (20,000 ft) a.s.l.

On 19 July seismicity increased markedly, interpreted as possibly indicating that ash plumes rose to altitudes of 7.6-9.1 km (25,000-30,000 ft) a.s.l. The Volcano Alert Level was raised to Warning and the Aviation Color Code was raised to Red. The next day, seismicity declined again and the Volcano Alert Level was lowered to Watch and the Aviation Color Code was lowered to Orange. Satellite imagery revealed that an ash plume about 20 km from Okmok drifted SE at an altitude of 3.7 km (12,000 ft) a.s.l. Additional ash plumes observed on satellite imagery and spotted by pilots rose to altitudes of 4.6-6.1 km (15,000-20,000 ft) a.s.l. During 21-22 July, ash plumes rose to altitudes of 6.1-9.1 km (20,000-30,000 ft) a.s.l. and drifted SE.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Based on observations of satellite imagery, the Darwin VAAC reported that during 16-18 July ash plumes from Batu Tara rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted W. A thermal anomaly was noted on satellite imagery on 16 July.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

KVERT reported that intermittent volcanic tremor at Bezymianny was detected on 11 July and seismic activity was above background levels during 11-16 July. Weak thermal anomalies over the lava dome were detected in satellite imagery on 11 and 15 July. Hot avalanches were reported by local observers on 15 July. The level of Concern Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

SERNAGEOMIN reported that after two weeks of inclement weather around Chaitén, clouds cleared on 18 July and ash plumes were observed. During 18-21 July mushroom-shaped ash plumes emitted from the S sector of the new lava dome rose to an altitude of 2.5 km (8,200 ft) a.s.l. Occasionally, explosions would push the plumes to altitudes of 3 km (10,000 ft) a.s.l. The plumes drifted N and NW, affecting several areas on the coast. The Alert Level remained at Red.

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)

INGV-CT reported that an inspection of Etna's summit craters on 15 July revealed degassing from the Northeast Crater and to a lesser degree from the BN-1 crater of the Bocca Nuova. Explosive activity was restricted to Vent 2 of the active NW-SE-trending fissure E of the summit craters and characterized by weak Strombolian activity and diffuse ash emissions. During 15 and 17 July lava flows were active in the Valle del Bove. On 17 July, no explosive activity was seen along the fissure.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

Based on visual observations from HVO crews, video footage, pilot reports, and web camera views, HVO reported that during 16-22 July, lava flowed SE through a lava tube system from underneath Kīlauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex. The lava flowed into the ocean at the Waikupanaha ocean entry resulting in occasional explosions and a vigorous steam plume from contact with the water. Lightning was sometimes seen in the steam plume. Incandescence was observed from the TEB vent, rootless shields, breakouts along the W margin of the TEB lava tube, and from vents and sporadic spatter in Puʻu ʻŌʻō crater. The sulfur dioxide emission rate at Puʻu ʻŌʻō was very high at 6,300 tonnes per day on 17 July; the average background rate is about 2,000 tonnes per day.

During the reporting period, Kīlauea earthquakes were located beneath the summit area and beneath Halemaʻumaʻu crater, along S-flank faults, and along the E and SW rift zones. Beneath Halemaʻumaʻu crater, another 20-40 small earthquakes per day also occurred but were too small to be located. The vent in the crater continued to produce a white plume with minor ash content that drifted mainly SW. Night-time incandescence was seen at the base of the plume. Rock clattering, booming noises, and "rushing sounds" were heard in the vicinity of Halemaʻumaʻu crater. The sulfur dioxide emission rate was high and between 700 and 800 tonnes per day, during 16-18 July. The pre-2008 background rate was 150-200 tonnes per day. On 19 July, incandescent material was ejected from the vent.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

INSIVUMEH reported that during 9-16 July, Strombolian activity from Pacaya's MacKenney cone was mainly characterized by explosions approximately 2-3 minutes apart. Pyroclastic material was ejected about 25 m above the crater. Lava flowed 100-200 m down the NW flank and continued to slowly fill in the area between MacKenney cone and Cerro Chino crater to the N. On 16 July, fumarolic plumes drifted SW.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

RVO reported that during 12-18 July, ash plumes from Rabaul caldera's Tavurvur cone drifted NW and W. Ashfall was reported in areas downwind including significant accumulation in Rabaul town (3-5 km NW).

Source: Rabaul Volcano Observatory (RVO)

KVERT reported that seismic activity at Shiveluch was slightly above background levels during 11-18 July and possibly indicated ash explosions up to 4.5 km (14,800 ft) a.s.l. on 17 July. Moderate fumarolic activity was seen on 13 and 15 July. Observations of satellite imagery revealed a thermal anomaly on the lava dome during 10-11 and 13-17 July. The Level of Concern Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

MVO reported no evidence of lava-dome growth at Soufrière Hills during 11-18 July. Seismic activity remained low. The E talus slope continued to erode, producing minor rockfalls that descended into the Tar River Valley. Following a small swarm of volcano-tectonic earthquakes on 20 July, four eruptive events each produced ash plumes that rose to altitudes of 2 km (6,000 ft) a.s.l. and drifted W. The first two events generated plumes above the Tar River Valley possibly from small pyroclastic flows. Ashfall was reported in Old Towne. Rumbling noises were heard in nearby areas and lightning strikes were observed. The Alert Level remained elevated at 4 (on a scale of 0-5).

Source: Montserrat Volcano Observatory (MVO)

On 10 July, CVO lowered the Volcano Alert Level for Mount St. Helens to Normal and the Aviation Color Code to Green, following the cessation of lava-dome growth in late January and about five months with no signs of renewed activity. Earthquakes, volcanic gas emissions, and ground deformation were all at pre-eruptive background levels.

Source: US Geological Survey Cascades Volcano Observatory (CVO)

The IG reported that during 15-22 July, explosions from Tungurahua were detected by the seismic network. Although clouds occasionally inhibited visual observations, steam and ash-and-steam plumes were spotted and rose to altitudes of 7-10 km (23,000-32,800 ft) a.s.l. and drifted W and SW. On 19 and 22 July, nighttime incandescence from the crater was observed. On 20 July, lahars descended NW and S drainages. Ashfall was reported in areas downwind during 19-22 July. On 21 and 22 July, explosions vibrated windows in areas NW.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)